A breast pump has been widely used which is provided with a milk expressing section having a diameter enlarged into a trumpet shape which is abutted against a mother's breast, i.e., an enlarged-diameter milk expressing section.
In particular, a structure is known in which a recess is provided on an upper end and the like of a breast pump main body, in such a manner that breast milk which has turned into a mist due to the negative pressure during expression of milk does not leak out externally, and a deforming member, such as a diaphragm, is accommodated inside this recess.
More specifically, a manual breast pump has been known in which an operating section such as a handle is coupled to the diaphragm, and a negative pressure is generated by repeatedly lifting up the diaphragm by reciprocal movement of the handle. As a manual breast pump of this type, there is the breast pump of Japanese Patent No. 4413231 offered by the applicants (Patent Document 1).
The breast pump according to Patent Document 1 can be disassembled and assembled easily for cleaning, whereas the operating section cannot been removed easily when operated.
Consequently, this breast pump has an accommodating vessel 11 for storing breast milk, a breast pump main body 21, and a handle 61 which is attached to the breast pump main body 21 and functions as an operating section for deforming a negative pressure generating member 30 installed on the breast pump main body. An engaged structure 62 which is positioned at one end of the handle 61 moves reciprocally up and down as indicated by an arrow B due to rotating about an axle section 49, as shown in FIG. 2 of Patent Document 1.
Here, as shown in FIG. 1 of Patent Document 1, when a user operates the lever section 63 in the direction A2, i.e., so as to approach a bottle 11, and the engagement structure 62 thereby moves in the direction of an arrow B2, then a second wall section 32, which is a deforming section of the negative pressure generating member 30, is caused to deform so as to face towards the upper side from a state facing towards the lower side in FIG. 1. Therefore, when the volume of the internal space S formed between a bottom surface section 33 and an inclined surface 42 is increased, air from a milk expressing section air flow path 23 is drawn in, in accordance with the amount of air drawn into the internal space S, and when a user's breast is abutted against the enlarged-diameter front end of the milk expressing section 22, a hermetic space which is an internal space is formed, and therefore the milk expressing section air flow path 23 assumes a negative pressure. Milk is expressed by this negative pressure.